A Word on Flat Plates
Flat plate collectors only provide a useful amount of heat during the summer months in the UK. due to their
popularity of flat plate collectors is their cheap construction - you can build one yourself for a few pounds
worth of scrap material, or you can buy one for £300-500. This is typically a lot cheaper than evacuated tube
panels, which typically cost £800-1200.......until now! Don't fit a dinosaur!
Vacuum tube collectors will provide useful heat for 12months of the year, as long as the sun is shining, and
can even produce heat in overcast weather. (In April, an overcast day without any sunshine is still able to
heat a 210litre hot water cylinder to 40°C)
A Word on Plastic Pipework
There are some flat plate systems for sale in the UK, such as the Solar Twin system,
which use plastic, silicone or rubber pipework, which makes installations easier and
to reduce costs. Whereas this pipework may be ideal for flat plates, it is definitely not
adequate for evacuated tubes. On a hot sunny day, flat plates may heat water up to
a temperature of 60°C. Evacuated tube systems are capable of heating the waterbeyond
140°C. Most plastic pipework has a working temperature of no more than 65°C, and is
able to stand no more than 90°C - so you should always use copper for solar installations.

These are the basic features of the kit:
•        20 vacuum heat tubes with copper heat pipe and internal high efficiency heat collector
•        1.5m tubes, 47mm diameter
•        Frame area of 2.25m2
•        Heat Reflectors which mount in the gap between tubes (to increase efficiency further)
•        Full instructions (downloadable above)
•        Kit is supplied as two compact boxes (162x28x24cm, 172x18x27cm) which can easily be transported
in an
average car
•        You can buy the other components from me, or from elsewhere - you chose!

Solar energy is the cleanest and most inexhaustible of all known energy sources. Solar radiation is the heat,
light and other radiant energy that is emitted from the sun. The sun's energy, although plentiful, has been
hard to directly harness until recently.
Solar water heater converts solar energy into thermal energy, then heat the water step by step. The beauty
of this system is it does not create pollution or harmful emissions, and is extremely economical - the fuel
(sunshine) is free! Plus, they are environmentally friendly. To take full advantage of these heaters, you
should ideally have an unshaded, south-facing location (a roof, for example) on your property, although they
can be utilised at ground level also. This type of Solar water heater is now extremely popular in many areas
of the world, are  now becoming much more popular in the UK, due to their high efficiency.
Until now, solar panels were not particularly popular in the UK due to their low efficiencies during the spring,
autumn and winter months. Classic solar panels (flat plate collectors)  work equally well as radiators - and
therefore unless ambient temperature is high, heat losses are considerable. Flat plate collectors, despite
their poor performance at UK lattitudes, have remained the panel of choice until now, due to their low cost,
and DIY-suitability. However, we are now able to offer much higher efficiency vacuum tube collectors at
similar prices to flat plate collectors.
Key Benefits of Vacuum Tube Solar Panels:
•        High temperature output even in cold weather
•        Warms water even during winter, as long as the sun is shining
•        Produces heat even in overcast weather
•        Easy to fit
•        Higher efficiency and greater installation flexibility with heat to many of the more expensive brands on
the market - as the tubes and headers are all manufactured in the same factory by an OEM supplier
.


Below explains all about solar water heating and twin coil tanks.  Go to FAQ
solar for more info
EVACUATED TUBE SOLAR HOT WATER PANEL (20 tube)
These top-of-the-range solar panel heat collectors are suitable for heating
domestic hot water, swimming pools etc - even in the winter! One unit is
adequate for an average household (3-4people), and it is modular, so you can
add more if required. A single panel is sufficient for a 200litre cylinder, but you
can fit 2 or more for high water usage, or for heating swimming pools or
underfloor heating. Some types of renewable energy are only available in certain
locations, however free solar heating is potentially available to almost every
house in the UK! Every house should have one -really! And with an overall
efficiency of almost 80%, they are much more efficient than electric photovoltaic
solar panels (efficiency of 7-15%). And if we compare them on a like-for-like
basis, the price of a Solar Water Heater is around 30p/watt (compared to
£6+/watt for solar photovoltaics!)  
 
An assembled 20 tube standard panel and 10 tube high efficiency panel
This high tech unit concentrates the sun's energy at the tip of the copper 'heat
tube' - like a solid state magnifying glass!
The vacuum tube solar panel has been around for over 10years, and has proved
to be reliable and dependable. The vacuum tubes consist of a double wall glass
tube (made from strong borosilicate glass ie pyrex) with a space in the centre
which contains the heat pipe. The sun's radiation is absorbed by the selective
coating on the inner glass surface, but prevented from re-radiating by the
silvered innermost lining. This is in effect like a one-way mirror which has been
optimised for infra-red radiation. In fact it is very efficient, of the sun light's energy
hitting the tube's surface, 93% is absorbed, whereas only 7% is lost through
reflection and re-emission. The presence of the vacuum wall prevents any losses
by conduction or convection - just like a thermos flask. Because of this, the
system will work even in very low temperatures, unlike traditional flat plate
collectors. This is why our system can be used to heat up water at the South
Pole Antarctic Science Base - where ambient air temperatures can drop below
-40°C
The heat transferred to the tip of the heat pipe is in turn transferred to a copper
manifold in which water circulates to heat the domestic hot water tank .If a tube is
placed in direct sunlight on a summer day, the tip temperature can reach 250°C
- so the system easily heats domestic hot water cylinders to 60°C even in cooler
weather! The manifold is heavily insulated with a 2" thickness of pre-formed
rockwool to keep the heat in. Unlike flat plates, these headers are so well
insulated that they should not require antifreeze in normal operation - the
temperature of the header is unlikely to fall below 10°C even in very cold
weather. The more advanced solar controllers include a low- temperature facility-
should the temperature of the collector fall below a defined level, the pump will
operate to allow the water at the bottom of the tank to heat the collector slightly.
In normal conditions, this would never be necessary - but it acts as a good safety
margin.

How Much Heat Will I Gain?
Average Daily Irradiation (Insolation) Figures for Each Month of the Year:
(Solar energy reaching each 1m2 of the earth’s surface at UK latitudes)
Ideal for swimming pools hot tubs and spa's
Jan            Feb           Mar           Apr           May           Jun           Jul           Aug           Sep           Oct           Nov           Dec
MJ/m2 day                 2.3             4.2            7.0           11.6           15.0          18.0         16.0        13.0           10.0           6.0            2.8            1.7

kWh/day  
per m2                     0.64            1.17          1.94           3.22           4.17          5.00         4.44        3.61           2.78          1.67          0.78          0.47

Heat Gain from
1 panel per day   1.15kWh      2.11kWh    3.49kWh     5.80kWh     7.51kWh     9.00kWh   7.99kWh   6.50kWh   5.00kWh     3.01kWh   1.41kWh    
0.85kWh
How Do I Connect the Panel?
Pressurised Systems.
The drawing above is one example of how to connect the panel. This is a typical installation that would be
carried out by a professional installer, utlising a twin coil solar cylinder. These cylinders are far superior to a
standard domestic hot water cylinder  - and I can supply these up to around 500litres capacity! Typical solar
cylinders are 175 - 260litres. The additional water capacity allows the user to store heat for several days, to
even out variations in day-to-day insolation. A typical 210litre cylinder is £320. The diagram above shows how
the solar loop can be operated as a pressurised system - this is almost universal for various reasons:
•        Ease of fitting
•        Not limited by headroom in the loft area
•        Most cost effective solution in terms of components and fitting time
•        Can allow operation above 100°C (eg if you run your system at 1bar, the water will not boil until it
reaches 120°C)

What else will I need to go with this panel?
It depends on your application and the method you employ. The simplest system would be based on thermo-
siphon (convection or 'gravity feed'). The panel would be mounted lower than the hot water cylinder, when the
sun shines, the hot water will rise, and displace the colder water which returns to the panel. This system
requires no additional energy, no control system and is self-regulating, simple, cheap and effective - but not
very convenient for most situations. In this case, you will only require the header tank or pressurised system kit
plus copper tube and insulation.A typical system would normally include:
•        Solar panel
•        Solar Hot Water Cylinder (eg 210litre £320, 175litre £290)
•        Pressurised System Kit (£65)
•        Controller and temperature sensors (Basic Resol B1 £65, or Resol Delta
Sol B with display and additional control features £130)
•        Pump and Isolation Valves £42
•        Non Return Valve to prevent siphoning (not absolutely necessary with
evacuated tube systems, but will increase efficiency slightly) £3.50
•        Copper pipework, fittings and pipe insulation (obtain from any good DIY
or Builders' Merchant)
What about Swimming Pools?
Swimming pools are an ideal application for solar water heating, as the
temperature required is quite low - under 30°C. Most installers will recommend
flat plates to keep the price down - because the amount of panels required is
much larger than for heating domestic hot water - however, if you can buy a high
efficiency evacuated tube solar panel for the same money - you might as well
enjoy solar heated pool water all year round - instead of just in July and August!
If you used flat plates, a rule of thumb for calculating what you need is to fit the
equivalent of 50% of the pool's surface area. For Vacuum tube panels, this is
reduced to 25% - and of course, they will carry on working in the autumn, winter
and spring.  A panel is 2.25m2 so each panel will heat 11m2 of pool area. A
40m2 pool would only need 4  panels  Compare this to the cost of heating a
pool for a year!
Installation is very simple. If you have chlorine you will need to fit a stainless steel heat exchanger (this is
because chlorine causes copper to corrode). These are available from pool suppliers (they are needed for
conventional heating methods for the same reason). If you dont have chlorine, you can simply put the solar
panel in-line with the pool filter, so that the pump directs water through the panel before returning it to the
pool. As the panel will NOT radiate heat on cold days, heat losses will be confined to your pipe runs only -
so you do not necessarily need a controller, although one can be fitted, to control a 3-way solenoid valve to
divert the water through the panel when the panel is hotter than the pool water.
This system is ideal for both
indoor and outdoor swimming pools. The system will give you use of your swimming pool for more months of the year
- and will dratically reduce heating costs. It will pay for itself within the first twelve months by reducing the cost of
heating the swimming pool. After the first year you will be using your pool and the costs will be reduced giving you
100% savings on your energy costs. If you got the pool why after the expence live by swimming in a cooler than you
want swimming pool or paying extremely high energy bills. Make the sensible change today and have your swimming
pool at the temperature you want and heated cheaply. This new system is efficient and cheap to purchase and
install. Its also a bonus by being good for the enviromentThis system is affordable and ideal for both local authority
swimming pools and domestic swimming pools.
Evacuated Tube Solar Collectors:
Don't wait till energy increases further throwing money down the drain, heat your hot tub or spa for free.You only
need to use domestic energy to add a little extra heat on cold cloudy days, even on cold cloudy days it will
partially heat the water in your hot tub so still saving money on energy consumption.
At current prices alone you will cover the cost of this new solar energy heating your spa or hot tub within 12
months
Of course it is - Energy prices are rising and forcasts are for it to continue to.
Is your spa or hot tub getting expensive to heat?
Spas and Hot tubs
WELCOME TO BOB STRATFORD
ALTERNATIVE ENERGY
SOLAR WATER
Counter
Thermal Store Coil - add £230 (provides mains pressure hot water)
•        Shower Coil - add £75 (provides mains pressure hot water for shower use only)
•       Additional Heating Coil (eg for woodburner) £55
•        triple layer insulation £25
•        horizontal cylinders - add £120 to above prices plus £45 for cradle
•        underfloor heating coil - add £145
Size
Water capacity
Expansion vessel
capacity
Weight
Retail price
1050 x 400
120
12 litres
160kg
£1150
1200 x 400
140
12 litres
181kg
£1195
1500 x 400
165
18 litres
212kg
£1250
1200 x 450
165
18 litres
212kg
£1265
1500 x 450
210
18 litres
271kg
£1275
1500 x 500
250
25 litres
386kg
£1495
1800 x 500
300
25 litres
386kg
£1575
10 tube 47mm (double-walled) panel
£220
20 tube 47mm (double-walled) panel
£395
30 tube 47mm (double-walled) panel
£570
20 tube 58mm (double-walled) panel
£560
30 tube 58mm (double-walled) panel
£825
10 tube 70mm single-walled panel
£485
20 tube 70mm single-walled panel
£950
roof mounting kit for 10/20 tube panel
£9.50
flat roof mounting kit 20 tube
£25
flat roof mounting kit 30 tube
£37.50
Accessories:
Pressurised system kit
£69
Thermostatic mixer valve
£39
Solar controllers
Standard Vented Copper Solar Cylinders:
All provided with twin coils - one boiler coil and one high surface area solar coil.
         Size            Water Capacity                            
1050x 400       120 litres         £420  
1200x400        135 litres        £420
1500x400        172 litres        £420
1800x400        210 litres        £465
1050x450        144 litres        £420
1200x450        168 litres        £435
1500x450        216 litres        £472
1800x450        259 litres        £564
1800x500        320 litres        £753
1800x550        450 litres        £poa
1000 litres        £poa
1300 litres        £poa
Resol A / Resol B1 Basic Solar Controller
£75
Resol Delta Sol BS/3 Solar controller (with dual digital
temperature display)
£130
Resol delta Sol BS/4 Solar controller (with dual digital
temperature display and variable pump speed control)
£150
Resol Delta Sol B Pro Solar Controller(control for two pumps -
for East/West orientated panels)
£175
Additional Temperature Sensors
£16
RETRO-FIT COILS - to replace immersion heater 0.65m long
£110
All twin coil units are supplied with Control pack.   

Control pack on all units consist of, Pressure reducing valve, Check valve, Expansion valve, Temperature relief
valve, 1 Dual aquastat, 1 zone valve, Expansion vessel with hose fixing kit, Pre-piped tundish      Braze 2 no:1/2"
female connection in standard position  

n.b. When measuring for a solar cylinder, please remember to account for the double thickness of insulation
(50mm)- this adds 100mm to the total tank diameter.
Mains Pressure Hot Water Cylinders
New breakthrough mean's it's cheaper to make solar panels to heat your swimming pool,You can even heat it to
80% in winter. Benefits of fitting solar panels for your pool - use your pool all year not just summer -solar panel will
take away the cost of gas and electric Solar panels can pay for them selves in one year - so cheap and easy to fit.
Solar panels can cost less than the amount you will save in heating costs for one year. Every year after is a bonus
and they can last in excess of 25 yrs. Also use solar panels to heat your domestic hot water or your hot tub. The
panels will supply more energy than you need in summer and most if not all that you need in winter here in UK